Impossible to walk on the landscape

Hello everyone,

I think my map is corrupt since I placed another landscape to visualize mountains in the background but which I have since deleted.

And now there is an invisible line on the map that doesn’t allow me to move around the landscape.
Even on a completely flat new landscape.

To visualize this “invisible line” Here is a video:

And if I ever walk into the “bugged” part, here’s what happens.
The game forces my character in one direction and pushes him quickly. Here is a video:

Do you have an idea of ​​how to resolve this problem ?
Thanks,